1. Field of the Invention
The present invention relates generally to computer-implemented graphics systems, and in particular, to a method, apparatus, and article of manufacture for performing visual annotative clipping in a computer-implemented graphics system.
2. Description of the Related Art
Computer-implemented graphics systems have been widely used by designers, illustrators, drafters, and engineers for a number of years. In most computer-implemented graphics systems, there are objects such as text or other annotation that should be displayed or plotted with a clear area around them for legibility.
In current products, this may be accomplished by placing a solid object having a color that contrasts with the color of text in the display order immediately proceeding and as a background to the text item. Alternatively, this may be accomplished by placing a solid object having a color that is the same color as the background of the display screen or print or plot media in the display order immediately proceeding and as a background to the text item. These techniques create a clear space for annotation whenever the drawing is displayed, printed, or plotted.
The drawbacks associated with these approaches are manifest. One problem is that these approaches will work only if xe2x80x98rasterxe2x80x99 type (and not vector type) output devices are used. Another problem is that the display order must be correctly maintained at all times. Yet another problem is that the user is responsible for insuring that no overlapping items are created.
Consequently, there is a need in the art for improved techniques for creating clear zones for text or annotations. Specifically, there is a need in the art for improved techniques for performing visual annotative clipping for clear zones.
To address the requirements described above, the present invention discloses a method, apparatus, and article of manufacture for performing visual annotative clipping, wherein the graphics objects in a document that include one or more clear zones are identified and collected into a clear zone list, and then all graphics objects in the document are compared to the identified graphics objects in the clear zone list to determine what elements of the compared graphics objects should be clipped because they extend into the clear zones.